Definition:When a figure can be rotated some amount and it still looks the same.
Another example:
This figure has can be rotated 3 times and it will look the same each time.
More examples:
Notice that some figures can have rotational and reflection symmetry. From the examples above, the first and third figures have reflection symmetry as well:
Does this shape have rotational symmetry?
Answer: No. If a shape fits itself once, it has no rotational symmetry. If we rotate the clover, it will not look the same until it is back in it's original position, so it only fits itself once.
This page will take you through two types of symmetry:
1) Reflection/Line Symmetry
2) Rotational Symmetry
Reflection Symmetry/ Line Symmetry
Definition: A type of symmetry in which one half of the figure is the mirror image of the other.
Line of Symmetry: A line that divides a figure into two equal parts, each of which is the mirror image of the other.
Examples:
The left half of the butterfly is the mirror image of the right half.The dotted red line is the line of symmetry in this example.
The figure can have a line of symmetry that is diagonal or horizontal too!
A figure can also have more than one line of symmetry! For example:
Worksheets:
Reflection Symmetry Printable Worksheet #1
Reflection Symmetry Printable Worksheet #2
Reflection Symmetry Printable Worksheet #3
Rotational Symmetry
Definition: When a figure can be rotated some amount and it still looks the same.
Another example:
This figure has can be rotated 3 times and it will look the same each time.
More examples:
Notice that some figures can have rotational and reflection symmetry.
From the examples above, the first and third figures have reflection symmetry as well:
Does this shape have rotational symmetry?
Answer: No.
If a shape fits itself once, it has no rotational symmetry. If we rotate the clover, it will not look the same until it is back in it's original position, so it only fits itself once.
Interactive activity: Click here to explore more about rotational symmetry
Rotational Symmetry Quiz: Click here to to test your knowledge on rotational symmetry!
Where else can we find symmetry?
There is reflection and rotational symmetry everywhere! Symmetry is all around us in the real world.
Here are some examples of reflection symmetry in nature:
Rotational symmetry in nature:
Watch a fun video of symmetry in the world!
Draw your own picture online with reflection and/or rotational symmetry!
Sources: